Spinning (textiles)

The yarn issuing from the drafting rollers passes through a thread-guide, round a traveller that is free to rotate around a ring, and then onto a tube or bobbin, which is carried on a spindle, the axis of which passes through a center of the ring. The spindle is driven (usually at an angular velocity that is either constant or changes only slowly) and the traveller is dragged around a ring by the loop of yarn passing round it. If the drafting rollers were stationary, the angular velocity of the traveller would be the same as that of the spindle and each revolution of the spindle would cause one turn of twist to be inserted in the loop of yarn between the roller nip and the traveller. In spinning, however, the yarn is continually issuing from the rollers of the drafting system and, under these circumstances, the angular velocity of the traveller is less than that of the spindle by an amount that is just sufficient to allow the yarn to be wound onto the bobbin at the same rate as that at which it issues from the drafting rollers.
Each revolution of the traveller now inserts one turn of twist into the loop of yarn between the roller nip and the traveller but, in equilibrium, the number of turns of twist in the loop of yarn remains constant as twisted yarn is passing through the traveller at a corresponding rate.
Natural fibres are from animals (sheep, goat, rabbit, silkworm), minerals (asbestos), or plants (cotton, flax, sisal). These vegetable fibres can come from the seed (cotton), the stem (known as bast fibres: flax, hemp, jute) or the leaf (sisal). Many processes are needed before a clean even staple is obtained. With the exception of silk, each of these fibres is short, only centimetres in length, and each has a rough surface that enables it to bond with similar staples.
In a spinning mule, the roving is pulled off bobbins and sequentially fed through rollers operating at several different speeds, thinning the roving at a consistent rate. The yarn is twisted through the spinning of the bobbin as the carriage moves out, and is rolled onto a cop as the carriage returns. Mule spinning produces a finer thread than ring spinning. Spinning by the mule machine is an intermittent process as the frame advances and returns. It is the descendant of a device invented in 1779 by Samuel Crompton, and produces a softer, less twisted thread that is favored for fines and for weft.
Hand spinning was an important cottage industry in medieval Europe, where the wool spinners (most often women and children) would provide enough yarn to service the needs of the men who operated the looms, or to sell on in the putting-out system. After the invention of the spinning jenny water frame the demand was greatly reduced by mechanisation. Its technology was specialised and costly, and employed water as motive power. Spinning and weaving as cottage industries were displaced by dedicated manufactories, developed by industrialists and their investors; the spinning and weaving industries, once widespread, were concentrated where the sources of water, raw materials and manpower were most readily available, particularly West Yorkshire. The British government was very protective of the technology and restricted its export. After World War I the colonies where the cotton was grown started to purchase and manufacture significant quantities of cotton spinning machinery. The next breakthrough was with the move over to break or open-end spinning, and then the adoption of artificial fibres. By then most production had moved to Asia.